dc circuit length?

[jcraft]

Does anyone know how far you can effectively run 24VDC. We have an application where we need to run it about 300' to a 1/2 amp load. Thanks

 

[ScottyUK]

Depends how thick the wire is and how big a volt-drop you can stand. For a 300' run you will be looking at a fairly heavy cable to keep volt-drop to reasonable limits. Post a bit more detail of your load and what supply variation it can handle and someone will probably give you a cable size.


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Sometimes I only open my mouth to swap feet...

 

[jcraft]

Basically it will be supplying two 24VDC siren/strobe lights for audio/visual status of a process. Each strobe is .56 amps. I would tend to think it could stand a drop of a couple volts. If anyone could give me a rough idea of wire size that would be great. Thanks

 

[itsmoked]

Here have a field day:

http://www.csgnetwork.com/voltagedropcalc.html

First find out the actual operating voltage requirements of your devices. Make sure you are clear on the round trip nature of your proposed circuit.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[sreid]

16 ga. wire has a resistance of 4 Ohms per 1000 feet. You have 600 ft. so the resistance is 4 x 0.6 = 2.4 Ohms. The voltage drop would be V = IR = 0.5 x 2.4 = 1.2 Volts

 

[OperaHouse]

It might be a good idea to put a 1,000 to 4,700uF at the end of that run since the type of loads you have are pulsing. Momentary current can be considerably higher than the average and this may cause problems.

Just yesterday I was playing with a GPS I had pucked up for $5 bucks with a battery case problem. My bench power supply had a 5 ohm resistor to jumper to the center connector so I could use a standard banana pair. The GPS draws less than .06A, but I couldn't get it to turn on till I shorted the 5 ohm resistor!

 

[logbook]

I note that you initially said a 1/2 amp load and now you are saying two 0.56A loads.

sreid's calculation is based on your initial data of 0.5A.

 

[LindyBob]

This should be about right:

600' (2x300)
24VDC

1.0 amp @ 3% drop => 8ga
0.5 amp @ 3% drop => 10ga
1.0 amp @ 10% drop => 12ga
0.5 amp @ 10% drop => 16ga

NOTE: Please be sure to adhere to ABYC standards

NOTE: Use ANCOR tinned & stranded wire in marine applications

 

[itsmoked]

American Boat and Yacht Council? Why??

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com